To see a list of options, run:
coverlet --help
The current options are (output of coverlet --help
):
Cross platform .NET Core code coverage tool 1.0.0.0
Usage: coverlet [arguments] [options]
Arguments:
<ASSEMBLY> Path to the test assembly.
Options:
-h|--help Show help information
-v|--version Show version information
-t|--target Path to the test runner application.
-a|--targetargs Arguments to be passed to the test runner.
-o|--output Output of the generated coverage report
-v|--verbosity Sets the verbosity level of the command. Allowed values are quiet, minimal, normal, detailed.
-f|--format Format of the generated coverage report[multiple value].
--threshold Exits with error if the coverage % is below value.
--threshold-type Coverage type to apply the threshold to[multiple value].
--threshold-stat Coverage statistic used to enforce the threshold value.
--exclude Filter expressions to exclude specific modules and types[multiple value].
--include Filter expressions to include specific modules and types[multiple value].
--include-directory Include directories containing additional assemblies to be instrumented[multiple value].
--exclude-by-file Glob patterns specifying source files to exclude[multiple value].
--exclude-by-attribute Attributes to exclude from code coverage[multiple value].
--include-test-assembly Specifies whether to report code coverage of the test assembly.
--single-hit Specifies whether to limit code coverage hit reporting to a single hit for each location.
--merge-with Path to existing coverage result to merge.
--use-source-link Specifies whether to use SourceLink URIs in place of file system paths.
NB. For a [multiple value] options you have to specify values multiple times i.e.
--exclude-by-attribute 'Obsolete' --exclude-by-attribute'GeneratedCode' --exclude-by-attribute 'CompilerGenerated'
For --merge-with
check the sample.
The coverlet
tool is invoked by specifying the path to the assembly that contains the unit tests. You also need to specify the test runner and the arguments to pass to the test runner using the --target
and --targetargs
options respectively. The invocation of the test runner with the supplied arguments must not involve a recompilation of the unit test assembly or no coverage data will be generated.
The following example shows how to use the familiar dotnet test
toolchain:
coverlet /path/to/test-assembly.dll --target "dotnet" --targetargs "test /path/to/test-project --no-build"
After the above command is run, a coverage.json
file containing the results will be generated in the directory the coverlet
command was run. A summary of the results will also be displayed in the terminal.
Note: The --no-build
flag is specified so that the /path/to/test-assembly.dll
isn't rebuilt
Coverlet can generate coverage results in multiple formats, which is specified using the --format
or -f
options. For example, the following command emits coverage results in the opencover
format instead of json
:
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --format opencover
Supported Formats:
- json (default)
- lcov
- opencover
- cobertura
- teamcity
The --format
option can be specified multiple times to output multiple formats in a single run:
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --format opencover --format lcov
By default, Coverlet will output the coverage results file(s) in the current working directory. The --output
or -o
options can be used to override this behaviour.
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --output "/custom/path/result.json"
The above command will write the results to the supplied path, if no file extension is specified it'll use the standard extension of the selected output format. To specify a directory instead, simply append a /
to the end of the value.
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --output "/custom/directory/" -f json -f lcov
Coverlet can output basic code coverage statistics using TeamCity service messages.
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --output teamcity
The currently supported TeamCity statistics are:
TeamCity Statistic Key | Description |
---|---|
CodeCoverageL | Line-level code coverage |
CodeCoverageB | Branch-level code coverage |
CodeCoverageM | Method-level code coverage |
CodeCoverageAbsLTotal | The total number of lines |
CodeCoverageAbsLCovered | The number of covered lines |
CodeCoverageAbsBTotal | The total number of branches |
CodeCoverageAbsBCovered | The number of covered branches |
CodeCoverageAbsMTotal | The total number of methods |
CodeCoverageAbsMCovered | The number of covered methods |
With Coverlet you can combine the output of multiple coverage runs into a single result.
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --merge-with "/path/to/result.json" --format opencover
The value given to --merge-with
must be a path to Coverlet's own json result format.
Coverlet allows you to specify a coverage threshold below which it returns a non-zero exit code. This allows you to enforce a minimum coverage percent on all changes to your project.
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --threshold 80
The above command will automatically fail the build if the line, branch or method coverage of any of the instrumented modules falls below 80%. You can specify what type of coverage to apply the threshold value to using the --threshold-type
option. For example to apply the threshold check to only line coverage:
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --threshold 80 --threshold-type line
You can specify the --threshold-type
option multiple times. Valid values include line
, branch
and method
.
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --threshold 80 --threshold-type line --threshold-type method
By default, Coverlet will validate the threshold value against the coverage result of each module. The --threshold-stat
option allows you to change this behaviour and can have any of the following values:
- Minimum (Default): Ensures the coverage result of each module isn't less than the threshold
- Total: Ensures the total combined coverage result of all modules isn't less than the threshold
- Average: Ensures the average coverage result of all modules isn't less than the threshold
The following command will compare the threshold value with the overall total coverage of all modules:
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --threshold 80 --threshold-type line --threshold-stat total
You can ignore a method or an entire class from code coverage by creating and applying the ExcludeFromCodeCoverage
attribute present in the System.Diagnostics.CodeAnalysis
namespace.
You can also ignore additional attributes by using the ExcludeByAttribute
property (short name or full name supported):
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --exclude-by-attribute 'Obsolete' --exclude-by-attribute'GeneratedCode' --exclude-by-attribute 'CompilerGenerated'
You can also ignore specific source files from code coverage using the --exclude-by-file
option
- Can be specified multiple times
- Use file path or directory path with globbing (e.g
dir1/*.cs
)
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --exclude-by-file "**/dir1/class1.cs"
Coverlet gives the ability to have fine grained control over what gets excluded using "filter expressions".
Syntax: --exclude '[Assembly-Filter]Type-Filter'
Wildcards
*
=> matches zero or more characters?
=> the prefixed character is optional
Examples
--exclude "[*]*"
=> Excludes all types in all assemblies (nothing is instrumented)--exclude "[coverlet.*]Coverlet.Core.Coverage"
=> Excludes the Coverage class in theCoverlet.Core
namespace belonging to any assembly that matchescoverlet.*
(e.gcoverlet.core
)--exclude "[*]Coverlet.Core.Instrumentation.*"
=> Excludes all types belonging toCoverlet.Core.Instrumentation
namespace in any assembly--exclude "[coverlet.*.tests?]*"
=> Excludes all types in any assembly starting withcoverlet.
and ending with.test
or.tests
(the?
makes thes
optional)--exclude "[coverlet.*]*" --exclude "[*]Coverlet.Core*"
=> Excludes assemblies matchingcoverlet.*
and excludes all types belonging to theCoverlet.Core
namespace in any assembly
coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --exclude "[coverlet.*]Coverlet.Core.Coverage"
Coverlet goes a step in the other direction by also letting you explicitly set what can be included using the --include
option.
Examples
--include "[*]*"
=> Includes all types in all assemblies (everything is instrumented)--include "[coverlet.*]Coverlet.Core.Coverage"
=> Includes the Coverage class in theCoverlet.Core
namespace belonging to any assembly that matchescoverlet.*
(e.gcoverlet.core
)--include "[coverlet.*.tests?]*"
=> Includes all types in any assembly starting withcoverlet.
and ending with.test
or.tests
(the?
makes thes
optional)
Both --exclude
and --include
options can be used together but --exclude
takes precedence. You can specify the --exclude
and --include
options multiple times to allow for multiple filter expressions.
You can also include coverage of the test assembly itself by specifying the --include-test-assembly
flag.
Coverlet outputs specific exit codes to better support build automation systems for determining failures and take action on it.
0 - Success.
1 - If any test fails.
2 - Coverage percentage is below threshold.
3 - Test fails and also coverage percentage is below threshold.
101 - General exception occured during coverlet process.
102 - Missing options or invalid arguments for coverlet process.